Dipper trip control



April 1939- G. E MILLER 2,152,907

DI PPER TRIP CONTROL Filed Sept. 27, 1938 2 Sheets-Sheet 1 April 1939- G. E. MILLER 235E361 DIPPER T RIP' CONTROL Filed ept. 27, 1958 -2 Sheets-Sheet 2 20 E I I F I IE2 I 31 7 34 F 1&4.

r 4/ Q A a) 8 II Patented Apr. 4, 1939 UNITED STATES PATENT OFFICE DIPPEB TRIP CONTROL Application September 27, 1938, Serial No. 231,948

4 Claims.

This invention relates to trip controls for the buckets or dippers of excavating or material transferring machines, and particularly to such a control of the fluid pressure type.

The primary object of the invention is the provision of a simple and efiicient control of this character which is easy and inexpensive both to apply to a machine and to operate, and enhances the practicability and commercial value of machines with which it is associated.

The invention is fully described in the following specification and one embodiment thereof illustrated in the accompanying drawings, in which-- Figure l is a fragmentary side elevation of a dipper type excavating machine with the trip control feature embodying the invention associated therewith;

Fig.2 is an enlarged fragmentary section on the line 2-4 in Fig. 1;

Fig. 3 is a fragmentary detail, in plan, of the trip line and its mounting means;

Fig. 4 is a fragmentary plan of the machine with the trip control feature embodying the inventlon in association therewith;

Figs. 5 and 6 are different vertical sectional details of one form of manual control employed in connection with the invention; and

Fig. 7 is a horizontal cross-section on the line 1-1 in Fig. 5.

Referring to the drawings, i designates an excavating machine of the dipper type, 2 the boom thereof, I the dipper, and 4 the dipper stick which has a rack and pinion connection with the boom and has its movement controlled in any suitable manner as well under stood in the art. In the present instance the hoist cable I for the dipper winds on a control drum 6. This drum is driven in any suitable manner, as through a gear I and such drive is controlled by'a clutch which is normally disengaged, and is engaged when one side of the associated vacuum cylinder 8 is open to a vacuum source, as well understood in the art. The cylinder 8 is in communication with a vacuum tank 9 or other suitable source through tubes II and II and an interposed manual controi it.

The trip line II for the trip it of the dipper 3, which may be of any suitable well known pull '0 type, passes, in the present instance, up from the dipper over an idler sheave I! on the dipper stick shipper shaft it carried by the boom, thence passes back around an idler sheave it anchored near the inner end of the boom and then forwardtoandwindsonandisauchoredtoadrum' 2| fixed on the shipper shaft. This shaft, which is drivenin any well known manner, as through a sprocket 2i thereon, has a rack pinion 22 fixed thereon and in driving engagement with a rack bar 23 on the dipper stick whereby a 5 turning of the pinion will shift the stick. The rack pinion and drum 20 turn in unison so that the trip line I! is paid out or slack therein taken up in accordance with the outward and inward movements of the stick. No novelty is claimed 10 for this.

The present invention resides in the trip control for the trip line I! and includes, in the illustrated embodiment, a vacuum cylinder 25 carried'by the boom at its inner end and a piston 20 15 therein from which a stem 21 extends and carries the sheave It. An outward vacuum actuated movement of the piston relative to the sheave imparts sumcient pull on the trip line it to release the dipper trip.

The outer end of the cylinder 25 is connected to the vacuum line it through the pipe 2! and control it. This control, in the present instance, is such that when the control handle ll thereof is in neutral position, as shown in Figs. 5 and 25 6, the communication between the vacuum source and both cylinders 8 and 25 is closed, and such communication is respectively open to one or the other of said cylinders when the handle is moved in one or the other direction from neutral posi- 30 tion, so that the pistons in the two cylinders may be selectively operated but not simultaneously.

One control of this type which is suitable for the purpose, but which in itself forms no part of this invention, is illustrated in Figs.5, 6 and 7. This control in itself is old, being purchased on the market, and will be described only sufllciently to enable its operation in connection with the present invention to be understood. This control includes a casing 31 having upper and lower sections divided by a partition member 32. The lower compartment is provided with four vertically disposed bores 33, II, 35 and It forming valve chambers which are rectangulsrly ar-- ranged with the chambers 83 and II diagonally disposed andeach in communication with a vacuum tube Iiv and with the chambers 85 and 3| likewise diagonally disposed and in communication with an air inlet tube 31. The partition member 82 has an opening therethrough from the top of each of said valve chambers It, It, II and SI into a respective chamber in the upper section of the control, the interior of said sectionforsuchpurposebelngcentrally dividedone u way by a vertical partition 3| and centrally the other way by a vertical partition IS. A separate valve 40 is disposed in each of said valve chambers and is normally held seated against the partition 82 to close the respective opening therein by an associated spring ll.

A stem 42 projects upward from each valve 40 within the associated compartment of the upper section in position to be acted upon by respective flngers 43 of the hand control lever 30. This lever is fuicrumed in the partition 38 crosswise of the partition 39. The lever 30 has four flngers 63, two at one side of the fulcrum and two at the other side, and positioned to act on the upper ends of the respective valve stems 42.

Each of the branch vacuum tubes i0 and II is connected to a respective pair of air and vacuum chambers, for instance, the tube l0 connects with the chambers and through a passage 45, which extends up through the easing into the partition I8 and thence opens crosswise of such partition into each of the upper compartments with which the chambers 33 and 35 are adapted to communicate when their respective valves are open. Likewise the vacuum tube 28 is connected to the chambers 34 and 36 through a passage located in the partition 38, which passage communicates at its upper end with both of the upper compartments with which such chambers connect, and with said chambers when their respective valves are open.

When the control lever 30 is in its neutral position, as shown in Fig. 5, both air valves 40, which are disposed in the respective chambers 35 and 36, are held slightly open so that air under atmospheric pressure will be admitted through the line I] and communicating air chambers 35 and 38 to both branch vacuum tubes in and 2! to relieve any vacuum action therein. When the lever is rocked in either direction from neutral position, one or the other oi the branch lines l0 and 28 is closed to the atmosphere by reason of the closing of the associated air valve, and is open to the vacuum source by reason of the opening of the associated vacuum valve 40.

Such movement of the control lever 30 also further opens the air valve on the same side of the lever as the vacuum valve, which is being opened, but this is immaterial as the other branch line with which such air valve is associated should be in communication with the atmosphere.

It is thus apparent that when the control lever 30 is in neutral position, both cylinders G and 25 are closed to the vacuum source and open to the atmosphere and that a rocking of the lever in either direction will open the vacuum source to one or-the other of said cylinders and close the air communication therewith, thus eflecting an application of the drum clutch in one case and the dipper trip in the other case. It is apparent that by providing a single control for the hoisting drum clutch and the dipper trip, the operator may move the control handle 30 in one direction from neutral to eflect a hoisting oi the dipper to proper position for dumping and may then after swinging the lever to neutral position,

effect a tripping of the dipper by simply swinging the control lever to tripping position without removing his hand from the lever, thus iacilitating the hoisting and tripping actions.

I wish it understood that my invention is not limited to any specific construction, arrangement or form of the parts, as it is capable of numerous changes without departing from the spirit of the claims.

Having thus described my invention, what I claim as new and desire to secure by United States Letters Patent, is:

1. In combination in a machine of the class described, a dipper, a hoisting means for said dipper including a hoist drum, a vacuum actuated drive clutch means for said drum, vacuum actuated trip means for said dipper, a vacuum source adapted to have communication with said clutch means and said trip means, and means normally closing the communication between said source and each of said clutch and trip means, and operable to selectively open the communication between said source and either of said means.

2. In a machine of the class described, in combination, a hoist drum control clutch, a dipper trip means and a pneumatic operating means common to both said clutch and trip means and having a unitary control member operable by movement from neutral to selectively cause engagement of said clutch or an actuation of said trip means.

3. In combination in a machine of the class described, adipper having a dump trip, a hoisting means for the dipper including a hoist drum, a diflerential fluid pressure actuated drive clutch for said means, a differential fluid pressure actuating means for the dipper trip, a diflerential fluid pressure source in communication with said drive clutch and trip actuating means, and means having a control member and operable to close the source communication to both said drive clutch and trip actuating means when the control member is in one position and to selectively open said source communication to said drive clutch and trip actuating means when the control member is in different predetermined positions of its movement from neutral.

4. In a machine of the class described, in combination, a hoist drum control clutch having an operating cylinder and plunger in connection therewith, a dipper trip means having an operating cylinder and plunger in connectiontherewith, a differential fluid pressure source in communication with each of said cylinders for operating the respective clutch and trip means, and means including a single control member operable to close both of said communications or to selectively open either communication.

GEORGE E. limit-EB 

